2019年饲料原料霉菌毒素污染状况调查

目的 调查分析2019年饲料原料霉菌毒素污染状况。方法 采用胶体金免疫层析法或上转发光免疫分析(up-conversion immunoassays, UPT)法对安佑集团各分子公司所采购的大宗饲料原料中呕吐毒素、玉米赤霉烯酮和黄曲霉毒素B1含量进行快速检测, 2019年度共检测饲料原料样品20918份。结果 对比安佑集团企业标准, 2019年饲料原料霉菌毒素污染总超标率为3.2%。饲料原料霉菌毒素污染整体情况由重转轻, 上半年污染较重主要是由于麸皮及次粉霉菌毒素污染超标所致, 下半年霉菌毒素污染程度整体较轻, 但9月玉米和玉米干酒糟及其可溶物(distillers dried grains with soluble, DDGS)的玉米赤霉烯酮(zearalenone, ZEN)污染情况较重, 其中DDGS达重度污染; 从产地来源看, 2019年全国各产地麸皮和次粉呕吐毒素(vomitoxin, DON)污染较重; 河南产地米糠黄曲霉毒素B1(aflatoxins B1, AFB1)及四川产地米糠ZEN达重度污染; 山东、江苏、云南、安徽产地玉米AFB1及安徽产地玉米DON达重度污染; 且饲料原料中的霉菌毒素并非单一存在, 多数情况下是多种毒素共存。结论 与2018年饲料原料霉菌毒素污染调查数据(未公开发表)相比, 2019年原料污染程度较轻。     

2020年饲料原料霉菌毒素污染状况调查

目的 为更好的指导饲料生产企业对原料质量的把控、采购及配方设计,汇总分析了2020年饲料原料霉菌毒素污染状况。方法 采用胶体金免疫层析法或上转发光免疫分析法（up-conversion immunoassays, UPT）对安佑集团各分子公司在2020年度所收集（含退货）的28519份大宗饲料原料中的呕吐毒素、玉米赤霉烯酮和黄曲霉毒素B1含量进行快速检测。结果 对比安佑集团企业标准,2020年饲料原料霉菌毒素污染总超标率为0.92%,污染整体情况较轻,其中上半年污染较重,主要由玉米副产物和次粉霉菌毒素污染超标所致,下半年霉菌毒素污染程度整体较轻,但第4季度玉米的玉米赤霉烯酮和黄曲霉毒素B1污染情况加重,玉米的霉菌毒素整体达中度污染;从产地来源看,2020年山东、湖北产地的麸皮和次粉呕吐毒素中度污染,四川、陕西产地的次粉重度污染;四川产地的米糠黄曲霉毒素B1达中度污染,山东产地的玉米呕吐毒素和江苏产地的玉米黄曲霉毒素B1达重度污染;且饲料原料中的霉菌毒素并非单一存在,多数情况下是多种毒素共存。结论 与2019年饲料原料霉菌毒素污染调查数据相比,2020年原料的霉菌毒素污染程度较轻。     

天津主要市售谷物的真菌污染状况调查

对天津市售大米、小米、黄米、黑米、江米、西米、泰国香米、大薏仁米、大麦仁、红豆、绿豆、大豆和玉米渣等13种市售谷物进行真菌污染调查。调查表明,市售谷物中真菌平均侵染率37.0%,其中泰国香米、小米、江米、黑米和黄豆等污染较轻,其侵染率明显低于大米、大薏仁米和红豆。米类谷物中的主要污染真菌为青霉、曲霉和交链孢霉,大豆中的优势菌为曲霉,其他豆类的优势污染菌为交链孢菌,玉米渣中主要为酵母菌和曲霉。     

袋装多味瓜子真菌污染状况

对４６份袋装多味瓜子（葵花子，南瓜子，西瓜子）进行了真菌污染的检测。３种瓜子真菌污染率及菌落计数均以葵花子为高（Ｐ＜０．００５，Ｐ＜０．０５）。葵花子外壳与种仁真菌污染及菌落计数亦有明显差别（Ｐ＜０．０５，Ｐ＜０．０２）。检出真菌２４３株；产毒真菌１１７株，占４８．１５％，频率较高。     

饲料的真菌污染及中毒

饲料霉变泛指被真菌进一步污染的饲料所呈现的发热——结块——霉变的综合质变过程,同时伴随着饲料中某些养分的氧化作用的发生。饲料霉变后,不仅营养物质平均要损失15%。左右,而且部分产毒菌株所产生的毒素还会降低饲料的适口性。当动物摄食感染的霉变饲料时,会使生长缓慢,发育不良,但死亡率不高,若动物采食被真菌污染严重的饲料,则会中毒、甚至死亡。此外,残留在饲料和畜产品中的霉菌毒索还可能间接(或直接)传递给人。因此,饲料霉变所带来的危害是不可低估的。     

山东省2018年饲料中黄曲霉毒素污染状况调查

为了了解山东省饲料黄曲霉毒素(AFB₁)污染状况,保证饲料质量安全,采集于山东省各地规模化动物养殖场、各大饲料厂及养殖户12 593份样品,利用上转发光竞争抑制免疫层析法测定黄曲霉毒素B₁的含量。结果表明,山东省饲料原料AFB₁超标率如下:玉米21.21%、玉米副产品2.35%～9.80%;饼粕类饲料超标率为10.00%～14.88%,米糠粕1.79%。配合饲料超标率如下:泌乳牛精料4.84%,鸡配合饲料1.02%～3.36%,鸭配合饲料3.25%～8.84%,猪配合饲料0.61%～5.17%,鹌鹑配合饲料12.24%,貉狐貂膨化饲料4.76%。     

山东临沂部分地区2012年产花生真菌污染调查

对山东临沂地区5个花生主产区2012年产花生真菌污染情况进行调查。方法 分别采集收获前1个月的花生和土壤样品,及收获期、收获后储存1个月、收获后储存3个月的花生样品,分别以点种法(花生样品)和稀释法(土壤样品)接种于马铃薯葡萄糖琼脂(PDA)平板,于(28±1) ℃培养5d后进行菌落计数并鉴定。结果 临沂部分地区花生样品100%受真菌污染。不同地区花生样品污染真菌的菌相不同,同一地区不同采样期花生样品污染的菌相也有差异;但各采样期花生样品中黄曲霉污染水平均较低(平均4.38%)。结论 山东临沂部分地区花生样品虽受黄曲霉污染较轻,但其它真菌污染严重,因此应加强花生种植、采摘、贮藏过程的防霉管理。     

我国部分省区2008年产小麦玉米中真菌污染状况研究

目的对安徽、江苏、河北、河南四省部分地区2008年产小麦、玉米真菌污染情况和菌相分布进行调查,为进行粮食中主要污染真菌产毒预测微生物学研究提供菌株,为粮食防霉提供依据。方法将采集的小麦、玉米样品消毒后点种于PDA培养基上,培养后进行菌落计数并鉴定菌相。结果四省小麦样品真菌污染率几乎100%,优势菌是交链孢霉;玉米全部样品均被真菌污染,优势菌是镰刀菌。结论四省的小麦、玉米样品真菌污染严重,粮食储藏过程中应采取必要的措施防止粮食霉变。     

Chromium concentrations in ruminant feed ingredients

Chromium (Cr), in the form of Cr propionate, has been permitted for supplementation to cattle diets in the United States at levels up to 0.50 mg of Cr/kg of DM since 2009. Little is known regarding Cr concentrations naturally present in practical feed ingredients. The present study was conducted to determine Cr concentrations in feed ingredients commonly fed to ruminants. Feed ingredients were collected from dairy farms, feed mills, grain bins, and university research farms. Mean Cr concentrations in whole cereal grains ranged from 0.025 mg/kg of DM for oats to 0.041 mg/kg of DM for wheat. Grinding whole samples of corn, soybeans, and wheat through a stainless steel Wiley mill screen greatly increased analyzed Cr concentrations. Harvested forages had greater Cr concentrations than concentrates, and alfalfa hay or haylage had greater Cr concentrations than grass hay or corn silage. Chromium in alfalfa hay or haylage (n = 13) averaged 0.522 mg/kg of DM, with a range of 0.199 to 0.889 mg/kg of DM. Corn silage (n = 21) averaged 0.220 mg of Cr/kg of DM with a range of 0.105 to 0.441 mg of Cr/kg of DM. By-product feeds ranged from 0.040 mg of Cr/kg of DM for cottonseed hulls to 1.222 mg of Cr/kg of DM for beet pulp. Of the feed ingredients analyzed, feed grade phosphate sources had the greatest Cr concentration (135.0 mg/kg). Most ruminant feedstuffs and feed ingredients had less than 0.50 mg of Cr/kg of DM. Much of the analyzed total Cr in feed ingredients appears to be due to Cr contamination from soil or metal contact during harvesting, processing, or both.     

山东省部分地区2018年收获玉米的真菌污染状况研究

目的 对山东省部分地区2018年产玉米表面污染真菌进行调查。方法 在马铃薯葡萄糖培养基(potato dextrose agar, PDA)上通过稀释涂布的传统分离培养方法获得真菌菌株, 利用传统的形态学与分子生物学技术相结合的方法对真菌种类鉴定。结果 共获得真菌菌株169株, 经形态学鉴定隶属于8属: 镰刀菌属(Fusarium), 青霉属(Penicillum), 曲霉属(Aspergillus), 交链孢属(Alternaria), 枝顶孢属(Acremonium), 梗霉属(Lichtheimia), 枝孢属(Cladosporium)、篮状菌属(Talaromyces)。其中, 镰刀菌(Fusarium)、青霉(Penicillum)、曲霉(Aspergillus)分离获得的数量最多, 镰刀菌种类是引起玉米穗腐病的主要病原菌, 其污染主要来自于田间。随玉米仓储时间延长, 优势真菌改变为青霉属和曲霉属。结论 山东地区玉米真菌污染初期以田间污染为主, 储藏过程中优势菌群受环境影响发生改变; 需要根据真菌污染状况改进提升传统果穗囤藏技术。     

Occurrence of mycotoxigenic fungi and mycotoxins in animal feed from bihar,india

A total of 387 samples comprising animal feed, poultry feed and cattle cakes from India were examined in order to isolate mycotoxin-producing fungi as well as mycotoxins. Of 385 Aspergillus flavus group isolates 53% were capable of producing aflatoxins in liquid SMKY medium. Toxigenic strains of other mycotoxigenic fungi, viz A ochraceus, A versicolor, Penicillium citrinum and Fusarium moniliforme, were also recorded. In feed samples, beside the aflatoxins present in 139 samples zearalenone, ochratoxin A and citrinin were also recorded alone or as cocontaminants. A monsoon climate together with the socioeconomic conditions of this region are important determinants for the high incidence of mycotoxins in animal food.     

The choline content of feed ingredients and mixed feeds determined by an enzymatic assay

A recently developed procedure for the determination of choline in ingredients and feeds was utilised to establish the levels and the variability of choline in a series of ingredients and to compare the analysed and calculated choline values of mixed feeds. The concentrations of choline in samples of maize (7), canola meal (3), wheat middlings (1) and dehydrated bakery product (1) were, respectively, 1·55±0·18, 7·59±0·08, 2·35 and 2·39 g kg⁻¹, all higher than ingredient composition table values. Choline contents lower than table values were found in samples of poultry by-products (7) and meat and bone meal (6): 2·18±0·87 and 1·08±0·29 g kg⁻¹, respectively. The average choline concentration found in samples of dehulled soybean meal (7) was 2·73±0·18 g kg⁻¹, similar to table values. The choline in samples of poultry fat (2) averaged 0·48±0·02 g kg⁻¹. Significant correlations between the concentrations of choline and of some components of the proximate analysis were found. The analysed choline concentrations in mixed feeds were only 1·4% lower than the calculated levels based on the ingredient analyses. The procedure was adequate for choline determination in ingredients or mixed feeds. The high variability in the choline content of some ingredients may require analysis for proper feed formulation. © 1998 Society of Chemical Industry.     

Apparent ileal digestibility of amino acids in feed ingredients determined with broilers and layers

The apparent ileal digestibility of amino acids in eight feed ingredients were determined using broilers and layers. The ingredients included three cereals (wheat, sorghum and maize), one cereal by‐product (wheat middlings), three oilseed meals (canola, cottonseed and soybean meals) and one animal protein meal (meat and bone meal). Dietary protein in the assay diets was supplied solely by the test ingredient. All diets contained 20 g kg^?1 acid‐insoluble ash as an indigestible marker, and each diet was offered ad libitum in mash form to five replicate pens of 42‐day‐old broilers and 60‐week‐old layers. The digestibility coefficients of most amino acids for wheat and sorghum were similar (P > 0.05) in broilers and layers. The digestibility of most amino acids for maize was higher (P < 0.05) in broilers compared to those in layers. The digestibility of individual amino acid for wheat middlings was higher (P < 0.05) in layers than in broilers. In general, the digestibility of amino acids for cottonseed meal, soybean meal, and meat and bone meal were similar (P > 0.05) between broilers and layers. The influence of class of bird on digestibility in canola meal was variable. The digestibility of threonine, valine, isoleucine, leucine, phenylalanine, glutamic acid and alanine were higher (P < 0.05), and those of methionine, histidine and lysine were lower (P < 0.05) in broilers compared to layers. These results suggest that the practice of using amino acid digestibility values generated with broilers for layers may not be appropriate for all feed ingredients. Copyright © 2006 Society of Chemical Industry     

Multimycotoxin and fungal analysis of maize grains from south and southwestern Ethiopia

The natural occurrence of fungi, mycotoxins and fungal metabolites was investigated in 100 samples of maize grains collected from south and southwestern Ethiopia in 2015. The maize samples were contaminated by Fusarium, Aspergillus and Penicillium species. Using liquid chromatography tandem mass spectrometry 127 secondary metabolites were analysed. Zearalenone was the most prevalent mycotoxin, occurring in about 96% of the samples. Zearalenone sulfate was the second most prevalent, present in 81% of the samples. Fumonisin B1 was detected in 70% of the samples with a mean level of 606 μg kg^?1 in positive samples, while FB2, FB3 and FB4 were detected in 62%, 51% and 60% of the maize samples with mean levels of 202, 136 and 85 μg kg^?1, respectively. Up to 8% of the samples were contaminated with aflatoxins, with a maximum level of aflatoxin B1 of 513 μg kg^?1. Results were higher than earlier reports for maize from Ethiopia.     

A survey of the fungal contamination and presence of ochratoxin A and zearalenone on Spanish feed and raw materials

The incidence of fungal contamination in 91 samples of feed and raw materials used for animal feeding in Spain has been studied. Sample analysis was accomplished in a new culture medium to which a beta‐cyclodextrin had been added, and a comparison with other more usual culture media was performed. Ochratoxin A (OTA) and zearalenone (ZEA) contamination of all the samples was evaluated by RP‐HPLC with fluorescence detection. The fungal genera found, such as Penicillium and Fusarium, included mycotoxigenic strains as OTA and ZEA (33.3 and 26.4% incidence respectively). One sample of corn and another of cotton seed were contaminated with levels of OTA above the 5 and/or 10 µg kg^?1 recommended by the legislation of several European countries, whereas none of the samples contaminated with ZEA surpassed the legislation limits suggested by the official agencies. Copyright © 2004 Society of Chemical Industry     

Incidence of toxigenic fungi and ochratoxin A in dried fruits sold in Brazil

A total of 117 dried fruit samples (black sultanas, white sultanas, dates, dried plums, dried figs and apricots) from different origins were analysed both for toxigenic fungi and for the presence of ochratoxin A. Amongst the fungi found, Aspergillus niger was predominant, with 406 isolates, of which 15% were ochratoxin A producers. They were followed by A. ochraceus, with 15 isolates and 87% ochratoxigenics, and A. carbonarius, with only five isolates of which 60% were ochratoxin A producers. The average infection rates for A. niger in black sultanas, plums, figs, dates and white sultanas were 22.0, 8.0, 4.0, 1.5 and 0.5%, respectively. The apricot samples were not contaminated by any fungi or ochratoxin A. Black sultana and dried figs contained the highest contamination with ochratoxin A, with 33 and 26.3% of the samples containing more than 5 µg kg^-1 respectively, while all the white sultanas, dates and plums had no sample that exceeded this limit.     

Precision nutrition: weighing feed ingredients correctly

The ability to mix a quality feed is often equated to the quality of the mixer; the ability to weigh ingredients correctly has received little attention. To assess how accurately feed mills weigh their ingredients, 14 feed mills specialising in swine diets were surveyed, which yielded 8432 data points (for 229 ingredients and 11–44 batch records per ingredient within mills). Amounts actually weighed (according to scale readings) were compared to calls, and differences were analysed statistically. Feed mills overdosed ingredients by 1.5 ± 16.3%: between mills, overdosing ranged from ?0.7 to 13.0%. Within ingredients, weighing variation ranged from 0.6 to 11.1% between mills and averaged 5.2%. Some of the weighing problems observed were attributed to discrepancies between the call size and the scale resolution. For example, weighing 11.3 units (pounds) on a scale with a 2 unit resolution leads to a minimum error of 6%. Such problems occurred for 8.7% of the calls and resulted in a minimum error ranging from 0.01 to 20%, averaging 1.95%. Poor choice of scales was the major source of errors in weighing, and the relationship weighing variation = 10^∧ [1.56 ? 0.50 log (call/scale resolution)] explained 40% of the variation observed (p < 0.05). Weighing ingredients in the right scale would thus not only benefit feed quality but also reduce diet cost, as it would reduce the overdosing of ingredients. © 2001 Society of Chemical Industry     

Aflatoxin B1, zearalenone and deoxynivalenol in feed ingredients and complete feed from central China

Between 2012 and 2014, 2528 feed ingredient and complete feed samples were collected from central China. Numbers of 2083, 255 and 190 samples were analysed for aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON), respectively, by high-performance liquid chromatography in combination with UV or fluorescence detection. The incidence rates of AFB1, ZEN and DON contamination of feed ingredients and complete feeds were 33.9%, 90.2% and 77.4%, respectively. The percentage of positive samples for AFB1 ranged from 13.1% to 97.1%. Cottonseed meal presented the most serious contamination by AFB1. ZEN and DON contamination levels of feeds ranged from 50% to 100%, indicating serious contamination over the studied 3-year period. This study demonstrates that AFB1, ZEN and DON contamination of feeds in central China is serious and differs over the years. Feeds are mostly contaminated with ZEN, followed by DON and AFB1.